1. Field of the Invention
The present invention relates to a pneumatically actuated gun for dispensing liquids, from among the various devices for applying gum used to seal containers.
This invention is applied to industrial processes in which speed of operation is a parameter as important as precision of the application, such as in packaging food products in metal tins.
The invention has a special construction of the gun that allows its installation in moving parts of machines or in industrial processes where the reduced weight and size are crucial.
2. Description of the Related Art
There are many guns or liquid application devices available in the market, but most are not designed for installation in moving parts, or are not pneumatically actuated, or are not as small and lightweight, or do not have the speed of operation of the invention described in what follows.
Installations for applying gum to steel or aluminium lids of tins using a sealant gum are of the type of Patent GB8308721, of W.R. Grace Ltd., of 14.10.82.
Patent EPO 0736332 by Rieck & Melzian GmbH is for an “Apparatus for applying gum to the edge portion of non-circular lids”, with a fixed nozzle and a revolving lid, synchronising a toothed wheel with a toothed disc having the form of the lid, so that the number of teeth of the disc is a multiple of that of the wheel, as well as having two control cams that adapt the position of the disc to that of the wheel maintaining the teeth engaged, while the other cam ensures that the opening of the injection nozzle is on the midline of the sealing band being deposited next to the edge of the lid.
Lastly, and more directly related, Patent PCT ES 02/00271 of the present applicant relates to a “Cutter-gummer for the edges of non-circular metal lids of containers” that incorporates among other elements a large revolving plate and a diversity of workstations housed in said plate and provided with edge-cutting and gumming devices, diametrically opposite each other, that works with any shape of lid or base, adapting to their geometry by revolving the lids in the workstations, in which the gumming apparatus inclines the gun with total precision to follow the top edge of the copying cam by a follower arm in any angular position with respect to the plane of attachment to the arm, fixed for each type of lid, directing the stream of gum towards the base of the lid and by centrifugal force to the inner face of the edge wing and to a substantial portion of the lower segment of its rounding, without producing any spillage of gum to the outside due to overflowing.
The applicant is not aware of any registrations of pneumatically actuated guns in which the operational speed, application precision, weigh and size parameters are decisive.